The present invention relates generally to DC/DC power converters. More particularly, the present invention pertains to the use and configuration of bus bars in an output stage of a DC/DC power converter.
Conventional DC/DC switch mode power converters use synchronous rectification on the output of the transformer isolating the primary and secondary circuits. The synchronous rectifiers are often implemented as MOS transistors in TO-220 electronic component packages attached to a heat sink. In such cases, the transformer and the MOS switches cannot be placed in close proximity to each other. This results in parasitic inductance, further causing ringing and hence overshoot of the voltage across the switches, which again requires an oversizing of the switches. Further, the physical separation of the transformer and the synchronous rectifiers result in significant conduction losses in the wiring.
With this type of package for the synchronous rectifiers, it is typically impractical or even impossible to increase the overall power density of the converter because of the size of the components. Further, the associated parasitic characteristics substantially prohibit an increase in the switching frequency.
It would therefore be desirable to provide new packaging methods in order to significantly increase the power capability of a center tapped DC/DC converter output stage to handle currents above 100 A, and at the same time decrease the space needed for the synchronous rectifiers and have low interconnection losses.